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A new bionic MAV's flapping motion based on fruit fly hovering at low Reynolds number

Acta Mechanica Sinica 2007年第5期23卷 485-493页

作者： Peng Bai Erjie Cui Feng Li Weijiang Zhou bingyan chen China Academy of Aerospace Aerodynamics Beijing 100074 China

On the basis of the studies on the high unsteady aerodynamic mechanisms of the fruit fly hovering the aerodynamic advantages and disadvantages of the fruit fly flapping motion were analyzed. A new bionic flapping motion was proposed to weaken the disadvantages and maintain the advantages, it may be used in the designing and manufacturing of the micro air vehicles （MAV＇s）. The translation of the new bionic flapping motion is the same as that of fruit fly flapping motion. However, the rotation of the new bionic flapping motion is different. It is not a pitching-up rotation as the fruit fly flapping motion, but a pitching-down rota- tion at the beginning and the end of a stroke. The numerical method of 3rd-order Roe scheme developed by Rogers was used to study these questions. The correctness of the numerical method and the computational program was justified by comparing the present CFD results of the fruit fly flapping motion in three modes, i.e., the advanced mode, the symmetrical mode and the delayed mode, with Dickinson＇s experimental results. They agreed with each other very well. Subsequently, the aerodynamic characteristics of the new bionic flapping motion in three modes were also numerically simulated, and were compared with those of the fruit fly flap- ping. The conclusions could be drawn that the high unsteady lift mechanism of the fruit fly hovering is also effectively utilized by this new bionic flapping. Compared with the fruit fly flapping, the unsteady drag of the new flapping decreases very much and the ratio of lift to drag increases greatly. And the great discrepancies among the mean lifts of three flapping modes of the fruit fly hovering are effectively smoothed in the new flapping. On the other hand, this new bionic flapping motion should be realized more easily. Finally, it must be pointed out that the above conclusions were just drawn for the hovering flapping motion. And the aerodynamic characteristics of the new bionic flapping motion in forwa

关键词： Flapping wing Low Reynolds number.MAV's Unsteady Numerical simulation

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Performance projections for ballistic carbon nanotube FinFET at circuit level

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Nano Research 2016年第6期9卷 1785-1794页

作者： Panpan Zhang chenguang Qiu Zhiyong Zhang Li Ding bingyan chen Lianmao Peng Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics Peking University Beijing 100871 China

A novel three-dimensional device structure for a carbon nanotube （CNT） fin field-effect transistor （FinFET） is proposed and evaluated. We evaluated the potential of the CNT FinFET compared with a Si FinFET at a 22-nm node at the circuit level using three performance metrics including propagation delay, total power dissipation, and energy-delay product （EDP）. Compared with a Si FinFET, the CNT FinFET presents obvious advantages in speed and EDP arising from its almost much larger current density but also results in a higher total power dissipation, especially at a low threshold voltage （V~ = 1/3Vaa）. A suitable improvement in Vth can effectively contribute to a significant suppression of leakage current and power dissipation, and then an obvious optimization is obtained in the EDP with an acceptable sacrifice in speed. In particular, CNT FinFETs with optimized threshold voltages can provide an EDP advantage of approximately 50 times over Si FinFETs under a low supply voltage （Vdd -- 0.4 V）, suggesting great potential for CNT FinFET-based integrated circuits.

关键词： carbon nanotube fin field-effect transistor(FinFET) integrated circuits multi-threshold voltage

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Realization of low contact resistance close to theoretical limit in graphene transistors

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Nano Research 2015年第5期8卷 1669-1679页

作者： Hua Zhong Zhiyong Zhang bingyan chen Haitao Xu Dangming Yu Le Huang Lianmao Peng Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics Peking University Beijing 100871 China

Realizing low contact resistance between graphene and metal electrodes remains a well-known challenge for building high-performance graphene devices. In this work, we attempt to reduce the contact resistance in graphene transistors and further explore the resistance limit between graphene and metal contacts. The Pd/graphene contact resistance at room temperature is reduced below the 100 Ω·μm level both on mechanically exfoliated and chemical-vapor-deposition graphene by adopting high-purity palladium and high-quality graphene and controlling the fabrication process to not contaminate the interface. After excluding the parasitic series resistances from the measurement system and electrodes, the retrieved contact resistance is shown to be systematically and statistically less than 100 Ω·μm, with a minimum value of 69 Ω·μm, which is very close to the theoretical limit. Furthermore, the contact resistance shows no clear dependence on temperature in the range of 77-300 K; this is attributed to the saturation of carrier injection efficiency between graphene and Pd owing to the high quality of the graphene samples used, which have a sufficiently long carrier mean-free-path.

关键词： graphene field-effect transistors contact resistance metal-graphene interface transfer length method

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Electric characteristic and cavitation bubble dynamics using underwater pulsed discharge

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Plasma Science and Technology 2019年第7期21卷 16-22页

作者： Minglei SHAN bingyan chen cheng YAO Qingbang HAN Changping ZHU Yu YANG Jiangsu Key Laboratory of Power Transmission and Distribution Equipment Technology Changzhou 213022People’s Republic of China College of Internet of Things Engineering Hohai UniversityChangzhou 213022People’s Republic of China Key Laboratory of Unmanned Aerial Vehicle Development&Data Application of Anhui Higher Education Institutes Wanjiang University of TechnologyMa’anshan 243031People’s Republic of China

Underwater pulsed discharge is widely applied in medicine, machining, and material *** induced cavitation bubble and subsequent cavitation collapse are considered the major motivations behind these applications. This paper presents an underwater pulsed discharge *** experimental setup is established to induce and investigate the cavitation bubble assisted with a high-speed camera. Three aspects, including the characteristic of the discharge with different applied voltages and conductivities, the evolution of the cavitation bubble profile, and the energy efficiency of cavitation bubble inducing, are investigated, respectively. Especially, the mechanism of pre-discharge time delay in the low field intensity case is explained using the Joule heat *** results show the validity of the underwater pulsed discharger and experimental setup. The present underwater pulsed discharger is proved to be a simple, portable, and easy-to-implement device for the investigation of cavitation bubble dynamics.

关键词： underwater pulsed discharge cavitation bubble electric discharge characteristic high-speed camera

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IGIgram:An Improved Gini Index-Based Envelope Analysis for Rolling Bearing Fault Diagnosis

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Journal of Dynamics, Monitoring and Diagnostics 2022年第2期1卷 111-124页

作者： bingyan chen Dongli Song Yao cheng Weihua Zhang Baoshan Huang Yousif Muhamedsalih State Key Laboratory of Traction Power Southwest Jiaotong UniversityChengdu 610031China School of Industrial Automation Beijing Institute of TechnologyZhuhai 519088China Institute of Railway Research University of HuddersfieldHuddersfieldHD13DHUK

The transient impulse features caused by rolling bearing faults are often present in the resonance frequency band which is closely related to the dynamic characteristics of the machine *** frequency band identification is a crucial prerequisite for envelope analysis and thereby accurate fault diagnosis of rolling *** this paper,based on the ratio of quasi-arithmetic means and Gini index,improved Gini indices(IGIs)are proposed to quantify the transient impulse features of a signal,and their effectiveness and advantages in sparse quantification are confirmed by simulation analysis and comparisons with traditional sparsity ***,an IGI-based envelope analysis method named IGIgram is developed for fault diagnosis of rolling *** the new method,an IGI-based indicator is constructed to evaluate the impulsiveness and cyclostationarity of the narrow-band filtered signal simultaneously,and then a frequency band with abundant fault information is adaptively determined for extracting bearing fault *** performance of the IGIgram method is verified on the simulation signal and railway bearing experimental signals and compared with typical sparsity measures-based envelope analysis methods and *** results demonstrate that the proposed IGIs are efficient in quantifying bearing fault-induced transient features and the IGIgram method with appropriate power exponent can effectively achieve the diagnostics of different axle-box bearing faults.

关键词： envelope analysis fault diagnosis frequency band identification improved Gini indices railway bearings

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Characteristics of water volatilization and oxides generation by using positive and negative corona

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Plasma Science and Technology 2022年第4期24卷 61-70页

作者： Ke chen Lianghao WAN bingyan chen Tao CHU Renyue GENG Deyu SONG Xiang HE Wei SU cheng YIN Minglei SHAN Yongfeng JIANG College of Science Hohai UniversityNanjing 210098People's Republic of China Nanjing Suman Plasma Science and Technology Co. LtdNanjing 211162People's Republic of China Jiangsu Key Laboratory of Power Transmission and Distribution Equipment Technology Changzhou 213022People's Republic of China College of Mechanical and Electrical Engineering Hohai UniversityNanjing 210098People's Republic of China

The physical and chemical properties have significant differences for the positive and negative charged particles generated by *** this work,a positive and negative corona discharge system was established,and two discharge reactors for charged particles restraining and acting were designed by a needle electrode covered with a quartz tube and a plate electrode filled with *** corona discharges happened within the needle-plate electrodes were excited by a positive and negative high voltage source,and the characteristics of both water volatilization and oxides generation were examined within influence of the distances of both quartz tube inside and *** results show that the characteristics of both the water volatilization and oxides generation can be affected by the distances of both quartz tube inside and *** the distances of tube inside were increased from 5.00 to 13.00 mm,the water volatilizations decreased under negative corona,and increased firstly and declined immediately under positive *** maximum value of the water volatilization appeared in the distances of tube inside with 6.00–8.00 *** addition,the concentrations of the HNO_(x) and H_(2)O_(2)in treated water decreased with increasing the distances of tube ***,with increasing the distances of tube outside from 4.00 to 14.00 mm,the change trends of both the water volatilizations and oxides presented the same as the distances of tube inside,and the maximum value of the water volatilization and oxides appeared in the distance of tube outside with about 9.00 ***,the positive corona can generate more water volatilizations and oxides in water than negative corona,and non H_(2)O_(2)can be produced by negative *** results reflect the difference between positive and negative corona interaction with water,which can provide reference for plasma application.

关键词： positive corona negative corona water volatilization oxides generation

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Synthesis of NO by rotating sliding arc discharge reactor with conical-spiral electrodes

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Plasma Science and Technology 2024年第9期26卷 97-108页

作者： bingyan chen Qi LIU Xu LI Chunyang ZHANG Xiangbin GUO Qingzhou YU Zhicheng TANG Xiang HE Wei SU Yongfeng JIANG College of Mechanics and Engineering Science Hohai UniversityNanjing 211100People’s Republic of China College of Mechanical and Electrical Engineering Hohai UniversityChangzhou 213200People’s Republic of China College of Materials Science and Engineering Hohai UniversityChangzhou 213200People’s Republic of China College of Information Science and Engineering Hohai UniversityChangzhou 213200People’s Republic of China

The present work investigates the potential applications of nitrogen oxides(NO_(x)),particularly nitric oxide(NO)and nitrogen dioxide(NO_(2)),generated through discharge plasma in diverse sectors such as medicine,nitrogen fixation,energy,and environmental *** this study,a rotating sliding arc discharge reactor was initially employed to produce high concentrations of gaseous NO_(x),followed by the utilization of a molybdenum wire redox reactor for NO_(2)-to-NO *** outcomes reveal that the discharge states and generations of NO_(x) are affected by varying parameters,including the applied energies,frequencies and airflow states(1.3-2.6 m/s are the laminar flow,2.6-5.2 m/s are the transition state,5.2-6.5 m/s are the turbulent flow),and the concentrations of NO_(x) within the arc discharge are higher than that in the spark ***,the concentrations of NO,NO_(2) and NO_(x) gradually increased,and the concentration ratios of NO/NO_(2) and NO_(x)/NO_(2) decreased with increasing the applied energy for one cycle from 14.8 mJ to 24.3 ***,the concentrations of NO,NO_(2) and NO_(x) gradually decreased,and the concentration ratios of NO/NO_(2) and NO_(x)/NO_(2) first decreased and then increased with increasing the applied frequencies from 5.0 kHz to 9.0 ***,the concentrations of NO,NO_(2) and NO_(x) gradually decreased,and the concentration ratios of NO/NO_(2) and NO_(x)/NO_(2) first increased and then decreased with increasing the air flow speeds from 1.3 m/s to 6.5 m/***,the concentrations of NO increased and NO_(2) decreased with increasing temperature from 25℃ to 400℃ using molybdenum *** findings provide experimental support for the application of plasma in the fields of medicine,nitrogen fixation,energy and environmental protection.

关键词： rotating sliding arc discharge NO_(x) synthesis of NO redox reaction

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Application of MIGP in Phosphate Rock Districts Development Planning and System Economic Evaluation

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Systems Science and Systems Engineering 1992年第1期2卷 46-56页

作者： ZHOU Xuejun, ZHONG Ziran, chen bingyan, ZHOU Qiumo, GUI Jingshe,ZHU Guangshu, ZHANG Xinqiang and chen Shaohui Institute of Planning and Design for Chemical Mines, Ministry of Chemical Industry

This paper, based on the study results of a subproject under the Seventh Five-year-plan National Major Scientific and Technological Research Project, will concentrate on the application of the mixed integer goal programming in the studies on the optimization and comprehensive evaluation of investment decision and production planning in Yichang phosphate rock district in Hubei Province and in Dianchi district in Yunnan Province. The optimization models for mineral district development planning system are formulated through system analysis. A microcomputer software based on the combination of mixed integer programming and goal programming is developed to continuously implement the calculation for the mathematical model with arbitrary objective priority levels and for a group of such models. And a system economic evaluation model is developed to measure the profitability of optimal planning system scenarios. Finally, a large amount of output information are provided for the reference of decision makers.

关键词： system analysis system optimization system economic evoluation system scenarios

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基于并行CFD和优化技术的返回舱外形多目标优化设计

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空气动力学学报 2015年第5期33卷 588-593,609页

作者：王荣陈冰雁中国航天空气动力技术研究院一所北京100074

在给定的质心设计范围内,围绕球冠倒锥返回舱外形的高超声速气动单点静稳定性、配平升阻特性、质心横偏量的综合设计问题,提出了多点多目标优化设计数学模型。通过多目标优化设计方法结合并行数值模拟技术,对该多点多目标气动外形优化... 详细信息

在给定的质心设计范围内,围绕球冠倒锥返回舱外形的高超声速气动单点静稳定性、配平升阻特性、质心横偏量的综合设计问题,提出了多点多目标优化设计数学模型。通过多目标优化设计方法结合并行数值模拟技术,对该多点多目标气动外形优化设计问题进行研究,为了加快多点数值计算进度,采用了嵌套并行方法,通过有效利用硬件资源来提高多个状态气动数值求解效率。根据以上方法给出的最优设计边界指出了返回舱单点静稳定性与配平升阻比和质心横偏量的矛盾关系,改善单点静稳定性会导致配平升阻比下降,使质心横偏量增加;反之,配平升阻比增加,质心横偏量减少都会使单点静稳定性变差。

关键词：返回舱优化设计并行数值模拟多目标单点静稳定性

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“浮空型”高空风力发电机关键参数变化影响规律研究

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太阳能学报 2019年第9期40卷 2449-2455页

作者：闫溟喻海川陈冰雁中国航天科技集团公司第十一研究院

针对一种'浮空型'高空风力发电机的各项总体参数建立相应数学模型,讨论浮空器几何尺寸、风速、风轮半径和转速变化对发电机运行高度和功率输出产生的影响,并分析各项参数对发电成本的影响规律。结果表明,以上各项参数均对发电机运行高... 详细信息

针对一种'浮空型'高空风力发电机的各项总体参数建立相应数学模型,讨论浮空器几何尺寸、风速、风轮半径和转速变化对发电机运行高度和功率输出产生的影响,并分析各项参数对发电成本的影响规律。结果表明,以上各项参数均对发电机运行高度和功率输出有非常明显的影响,通过合理优化各项参数,可获得最优参数组合方案。

关键词：高空风力发电运行状态功率输出发电成本

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